The present invention relates to visual fire alert systems and, more particularly, to novel and improved means for transmitting signals indicating the occurrence or possible occurrence of a fire to receivers positioned at selected locations for actuation to emit a flashing light or other visual alarm.
Smoke or heat-responsive detectors are commonly positioned within dwellings, public buildings, and other structures, to emit an audible alarm signal to warn individuals within hearing range of the potential presence of a fire in the structure. Such audible alarms are ineffective, however, for deaf persons or those with significant hearing loss. Accordingly, visual signalling systems have been devised for use in areas normally occupied by deaf or hearing-impaired individuals. For example, alarm or signal systems employing high intensity strobe lights are disclosed in U.S. Pat. Nos. 3,810,170 and 4,499,453. The former is designed to operate on 115v and/or 24v AC power, and the latter functions on DC within the range of approximately 4.5 to 40v. Although it is recognized that either system may operate on other power sources, it is nonetheless necessary to connect the individual signal devices to the power supply or distribution system by means of wiring provided expressly for such purpose.
Such wiring connections are eliminated by actuation of a lighting device by sound emitted from an audible smoke alarm, such as disclosed in U.S. Pat. Nos. 4,258,291 and 4,570,155, but these systems rely upon the audible device to provide the alarm and are intended to actuate a portable lamp for use in evacuating the premises. Another patent teaching the combined use of an audible alarm with an emergency light to assist in evacuation of the building is U.S. Pat. No. 4,199,754, wherein existing building wiring may be utilized for connecting one lighting device to the power source while a separately wired battery power supply operates the audible alarm and auxiliary or emergency lights. Other fire alert or alarm systems which include lighting means are disclosed in U.S. Pat. Nos. 4,074,225 and 4,305,069, as well as elsewhere in the prior art. The prior systems, however, all rely upon either self-contained circuitry in portable type devices or separately provided wiring connections to provide the necessary connection of the alarm device to the power source.
It is a principal object of the present invention to provide a fire or smoke alert system making full use of existing building wiring to supply an actuating signal to the alarm device.
A further object is to provide a fire alert system particularly directed to visual alarm devices distributed throughout a building and controlled from a remote location.
Another object is to provide a visual alarm signal for the hearing impaired employing plug-in alarm devices operable by signals transmitted over existing wiring circuits.
Other objects will in part by obvious and will in part appear hereinafter.